JPS58198736A - Sensor for pressure of fluid - Google Patents

Abstract

PURPOSE:To make simultaneous measurement possible, by using a direction perpendicular to a flowing direction of a fluid in a duct as the longitudinal direction and joining monolithically a total pressure measuring pipe of the upper stream side of the flowing direction having a total pressure measuring hole and a static pressure measuring pipe having a larger diameter than that of the total pressure measuring pipe having a static pressure measuring hole. CONSTITUTION:Plural total pressure measuring hales 4 are bored into a total pressure measuring pipe 2 so as to face an upper stream of a flowing direction A of a fluid. Total pressure is averaged in the pipe 2 because these plural holes 4 are communicated through the pipe 2. Plural Static pressure measuring holes 5 bored into a static pressure measuring pipe 3 are formed at a position having a suitable angle (a variable angle theta) to the direction A of the fluid. The static pressure is averaged in the pipe 3 because these holes 5 are communicated through the pipe 3.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a device for sensing the pressure (total pressure and static pressure) of a fluid flowing in a conduit.

Pitot tubes, orifice plates, etc. are used to measure the pressure of the fluid in the pipeline. When measuring the pressure of the pipe's own fluid using these pitot tubes, for example in the case of a blower performance test, the pipe cross-sectional area is divided into multiple equal parts.
The average pressure is obtained by arithmetic averaging the measured values at each dividing point of the Pitot tube (1) (Equal area cross section method of Pitot tube %JI88g330).

Although this method is suitable for testing the performance of blowers, it has various problems in actual operating sites, such as when fluids flow in air conditioner rooms or air conditioning piping. That is, when the above method is carried out at an actual operation site, it is difficult to determine the angle and position of the pitot tube with respect to the flow, and errors due to human factors are likely to occur. Further, the pressure distribution of the fluid with respect to the cross-sectional area changes from time to time, and unless measurements at each point are performed simultaneously, the true average value cannot be measured.

To solve this problem, a cylindrical rectifier tube with an opening in the flow direction of the pipe fluid is placed at each measurement point divided into multiple sections using the Pitot tube equal area cross section method, and the flow rate of the rectifier tube is A total pressure sensing part that senses total pressure and a static pressure sensing part that senses static pressure are provided at the end on the downstream side in the flow direction, and the total pressure sensing parts of each rectifier tube are connected by a total pressure manifold, and the static The pressure sensing parts are communicated with a static pressure manifold, and thin tubes are provided inside these manifolds, and these tubes average the total pressure and static pressure, respectively, so that the total pressure is transmitted from the total pressure manifold, and the static pressure is transmitted from the static pressure manifold. There is a device designed to measure However, this device has a complicated structure in which each manifold is a double pipe.

There are also 3-hole pitot tubes and orifice plates, but 3-hole pitot tubes have a complicated structure in which the interior of a cylindrical hollow body is divided into three chambers, whereas orifice plates have a simple structure and are located in one place. Although it is possible to measure the average value at the measurement points, there are disadvantages such as the pipe shape is limited and the pressure loss is large.

In view of the above-mentioned problems, the present invention was completed with the objective of providing a fluid pressure sensing device with a simple structure, capable of simultaneously performing measurements, and with low pressure loss. The pressure sensing device includes a total pressure measuring pipe having an appropriate number of total pressure measuring holes facing upstream in the flow direction, the longitudinal direction of which is perpendicular to the flow direction of the fluid in the pipe, and a flow direction. The total pressure measuring tube has an appropriate number of static pressure measuring holes at positions at appropriate angles, and the total pressure measuring tube is also a large diameter static pressure measuring tube, and the total pressure measuring tube and the static pressure measuring tube are It is characterized in that the static pressure measuring tube is integrally joined so as to be located on the downstream side.

The details of the fluid pressure sensing device of the present invention will be explained below based on the preferred embodiment shown in the drawings.

FIG. 1 shows a perspective view of the fluid pressure sensing device 1 of the present invention, and the direction of arrow A is the flow direction of the fluid.

As shown in the figure, the fluid pressure sensing device 1 of the present invention includes a total pressure measuring tube 2 made of a cylindrical hollow body and a static pressure measuring tube 3, the static pressure measuring tube 3 being located downstream of the total pressure measuring tube 2. It is constructed by integrally joining it so that it sticks.

In the figure, reference numerals 4, 4, . . . indicate total pressure measuring holes, which are bored in the total pressure measuring tube 2 so as to face upstream in the fluid flow direction A. The plurality of total pressure measurement holes 4, 4... are connected to each other via a total pressure measurement tube, so the total pressure sensed by each total pressure measurement hole 4, 4... is the total pressure. It will be averaged within the measuring tube 2. In the figure, 5, 5, . . . are static pressure measurement holes drilled in a plurality of static pressure measurement tubes 3, and as shown in FIG. It is formed in a position with .

These static pressure measurement holes 5, 5... communicate with each other via the static pressure measurement tube 3. Therefore, the static pressure sensed by each static pressure measurement hole 5, 5... is connected to the static pressure measurement tube 3. It will be averaged within 3. In this embodiment, the static pressure measuring holes 5.5... are formed as a pair of upper and lower holes, but it is also possible to form only one of them.

In the figure, 6.7 connects the tubes for guiding the average total pressure averaged within the total pressure measuring tube 2 and the average static pressure averaged within the static pressure measuring tube 3 to a measuring device, such as a manometer, etc. They are a total pressure outlet and a static pressure outlet. It is convenient to connect the pipes if the outlet ports 6 and 7 are threaded with female threads or provided with nirasol. Further, in this embodiment, the outlet is provided so that the pressure can be taken out from either side, but the outlet may be provided on either side.

In addition, in FIG. 3 and FIG. 9, the outer diameter of the fluid flow 3 is represented by d2, the pitch of the total pressure measurement hole 4 and the static pressure measurement hole 5 is represented by N with a subscript, and N1 and H7 are shown. are the distances from the respective nearer side end faces, and N2 to H6 are the distances to adjacent measurement holes. In addition, static pressure measurement holes 5, 5
The displacement angle between the perforated position and the fluid flow direction A is indicated by .theta. (as shown in the second figure).

The state of use of the apparatus of the present invention having the above configuration will be explained below.

Fig. S shows the state in which the fluid pressure sensing devices 1, 1, etc. of the present invention are installed in a pipe, but the required number of devices depends on the diameter of the pipe, the accuracy of the required measuring pressure, etc. It depends.

Fluid pressure sensing devices 1, 1... are installed in the pipe so that the total pressure measurement hole 4 faces upstream in the flow direction, and are installed in the total pressure collecting pipe 11 and static pressure collecting pipe 12 provided outside the pipe. The total pressure measuring tube 2 and the static pressure measuring tube 3 of each fluid pressure sensing device 1, 1, . . . are in communication with each other. Then, the total pressure collecting pipe 11 and the static pressure collecting pipe 12
If it is connected to a measuring device 13 such as a manometer, the average total pressure and the average static pressure can be determined, and it goes without saying that the average dynamic pressure can also be determined from the differential pressure between the two. In addition, in Figure 5, there is a total pressure collecting pipe 1 on the side surface that appears in the foreground.
1 and static pressure collecting pipe 12 are provided, but a total pressure collecting pipe and a static pressure collecting pipe are also provided on the opposite side so that the total pressure and static pressure are averaged by the collecting pipes provided on both sides. It is also possible.

In the figure, reference numeral 14 denotes a damper that adjusts the flow rate by changing the opening degree of the pipe line, and is provided downstream of the fluid pressure sensing devices 1, 1, . . . . The damper 14 changes the opening degree by changing the angle of the damper blade 15 with respect to the pipe by turning a handle 17 provided outside the pipe.

In this case, if the measuring device 13 is a flow meter, the flow rate can be adjusted while checking the flow meter, and it is also possible to automatically control the flow rate using the measured pressure as a signal. In the figure, P indicates the distance from the front edge of the total pressure measuring tube 2 of the fluid pressure sensing devices 1, 1, . . . to the damper shaft 16 of the damper A14.

Moreover, although FIG. S shows the case where the tube is installed in a square pipe, when it is installed in a circular pipe, it may be installed radially from the center.

Furthermore, although not shown, if the interior of the static pressure measuring tube 3 is divided into upper and lower λ chambers so that the static pressure can be measured individually in each chamber, the fluid can be It can also be used to sense the direction of flow. However, unlike a 3-hole pitot tube, which divides the interior of a cylindrical hollow body into three chambers, if the device of the present invention is applied, the interior of the static pressure measuring tube 3 is divided into two upper and lower chambers. Since it only requires partitioning, it has a simple structure and is easy to manufacture.

Next, a performance test was conducted on the fluid pressure sensing device of the present invention, and the failure will be explained below.

(Test 1) The fluid pressure sensing device 1 was set to have a pipe diameter of 300×lυθ.
The diameter of the static pressure measuring tube 3 is φ1g.
, θ is constant, and the diameter of the total pressure measuring tube 2 is φ6. O2
φ7.0. When φg, θ, and φ9.0 [drunk], the wind speed indicated by the fluid pressure sensing device 1 and the wind speed indicated by the pitot tube were compared and studied as a result of changes in the displacement angle θ of the static pressure measurement hole 5 under a constant wind speed state. .

In addition, since the flow in the pipe was to be uniform, the static pressure measurement holes 5 were only opened at / locations.

In addition, the external dimensions of the fluid pressure sensing device 1 used in the test are as follows:
Corresponding to the symbols shown in Fig. 3 and Fig. 3, L = λ9 [plot] t12 = / g, θ [fin] N + = /
00 (tm) Ny = /Deku [drunken] N
! :N3 =N4 =N5 =N6 = 0 (audience)
The diameter of the static pressure measurement hole 5 is /, 0 [simplified].

The test results are shown in Tables 1 to 1.

Table 1 shows the diameter d+fφ6 of the total pressure measuring tube 2. This shows the test results when θ [fight] is set, and the set wind speed is 9.9.
J (m/sec,), and the diameter of the total pressure measurement hole 4 is 521/
, 3C).

Table 1 shows the test results when dl is set to a'7.0 (simplified), and the set wind speed is 93 Cm/sec.
The diameter of the total pressure measurement hole 4 is assumed to be φ/, /, (nfi).

Table 3 shows the test results when the same < dt = dg, Oct1m], and the set wind speed was 9.93 (m / se
c, ), and the diameter of the total pressure measurement hole 4 is φ/, g (11s)
It's Toshide.

The test results are when the table d is I219.0 (TSA), and the set wind speed is 9. Q,? (fljl)
The diameter of the total pressure measurement hole 4 is one (OC fin).

The test results shown in Tables 1 to 9 are shown in FIG. In the same figure, the dashed line indicates the set wind speed of 9.93 (m/s
ee, ) and -〇-9-■-1-〇-2-〇-, the diameter dl of the total pressure measuring tube 2 is φ6.0. φ7.0゜φg,
The results are shown when o, φwo, and 0 (In).

(Test) The diameter of the static pressure measuring tube 3 was kept constant at φ1,0 (tILm), and the diameter of the total pressure measuring tube 2 was set at φ6,0,0. A test similar to (Test/) was conducted as φ7.0 CII Book).

The external dimensions of the fluid pressure sensing device 1 used in the test correspond to the symbols shown in Figures 3 and 3, and L = 297C.
d2=/Hiro, 0 [tIL Kasumi] N, = 10OC)
N7=/9ri[-]Nz =N3 =N4 =N
5 = N6 = 0 (mtn) Diameter of static pressure measurement hole 5
/, O (who) It is.

The test results are shown in Tables 5 and 6.

Table S 6 Table 5 shows that the diameter d1 of the total pressure measuring tube 2 is φ6.0 (mg:)
This shows the test results when the set wind speed was set to 9.
5/Cm/see, ), and the diameter of the total pressure measurement hole 4 is φ/, 3 [fin].

Table 6 shows the same < dx as φ7. (7(111111:
The test results are when the set wind speed is 9.3 / (
m/sec, ), and the diameter of the total pressure measurement hole 4 is φ/,
A[fifi] is.

The test results shown in Tables 5 and 6 are shown in FIG. In the same figure, the dashed line indicates the set wind speed of 9.5/(m/
sec, ) and -〇-2-〇- are the total pressure measuring tube 2, respectively.
6. The results are shown when O, Gua, and 0 (fall) are set.

(Test 3) The diameter of the static pressure measuring tube 3 is constant at r9.0[++li], and the diameter of the total pressure measuring tube 2 is 9! I3.0, 9! rt1.0,
A test similar to (Test/) was conducted with φS, 0 [Seagull].

The external dimensions of the fluid pressure sensing device 1 subjected to the test correspond to the symbols shown in FIGS. 3 and 9, and L = 297 Crn.
m) d2=9-OC1ntJL]N1=/θθ[my)
N7=/97C audience] N2=N3 officer N4 =N,
=N, = 0 (T) Diameter of static pressure measurement hole 5 /, 0 (T).

The test results are shown in Tables 7 to 9.

Table 7 Table g Table 9 Table 7 shows the test results when the diameter d1 of the total pressure measuring tube 2 is φ3.0 (Mm), and the set wind speed is 9.!
r 3 (m/sec, ), and the diameter of the total pressure measurement hole 4 is d 0.3 (m/sec).

Table g shows the test results when the same < dx is set to 125 tl, 0 (關), and the set wind speed is 9.!S3 (m/
see, ), and the diameter of the total pressure measurement hole 4 is dO, Yctnm
] Toshishita.

Table 9 shows the test results when the same <aX is ljt, Ocmtm], and the set wind speed is 9. ! ; 3 (m/
sec, ), and the diameter of the total pressure measurement hole 4 is 51 /, /
(tnm:) Toshishita.

The test results shown in Tables 7 to 9 are shown in Figure g. In the figure, the dashed line indicates the set wind speed 9. s3Cm/s
ec,), -〇-1-■-2-〇- are the diameter d of the total pressure measuring tube 2, respectively, I21i3.0, 9! >%, 0,
It shows the result when flrjr is set to 0 [fight].

(Sen Hiroshi) The diameter d1 of the total pressure measuring tube 2 is φ9. OCfnm], and the diameter d2 of the static pressure measuring tube 3 is g/g, θ, and from the results shown in Fig. 6, the displacement angle at which the indicated wind speed is approximately equal to the indicated wind speed by the Pitot tube. θ, i.e. displacement angle θ
Static pressure measurement hole 5 is located at the position where the value is approximately 5-OCdeg.
Using a fluid pressure sensing device 1 with a pair of holes above and below, the wind speed was adjusted to 5. 2! ; Cm/sec, ) A comparative study was conducted between the indicated wind speed of the fluid pressure sensing device 1 and the indicated wind speed by the pitot tube.

The results are shown in Table 1O. Further, the test results are shown in FIG. 9, and the dash-dotted line in the figure represents the actual wind speed in the pipe.

Table 1O (25) (Test 5) In actual operation sites, it is common to use a plurality of fluid pressure sensing devices 1 that match the pipe diameter. 500×300 (119+1
) 5 fluid pressure sensing devices 1 in the vertical direction in the rectangular pipe line
was installed, and the accuracy was examined by determining the error from the pitot tube measurements.

The installation position of the fluid pressure sensing devices 1 is such that the distance between adjacent fluid pressure sensing devices 1 is approximately /00 (112), and those located above and below are approximately from the inner wall of the pipe! ;0 (set to 11111).

The external dimensions of the fluid pressure sensing device 1 used in the test correspond to the symbols shown in FIGS. 3 and 9, and L=! ;OOC fight)
dl=l,, OC) d,=/f, Oc] N1
=N7= tI/ (cod) N2 =Ns =Ns =Na = g 3 (cod) N
4 = g/yC〕 Diameter of total pressure measurement hole 4 7.0〔〕 Diameter of static pressure measurement hole 5 〔〕 2.0〔〕〝-〔〔 Displacement angle of pressure measurement hole 5, θ-'I OCdeg ) In addition, a pair of holes for measuring static pressure 5 was used at the top and bottom.

In addition, the straight pipe section of the pipe line should be properly connected to the fluid pressure sensing device 1.
A 10-mesh broken line is used as a rectifier on the upstream side of the pipe, and a damper 14 is provided on the downstream side at a position of P=220C1Lm as shown in FIG. 3, and the damper blade 15 of the damper 14 is adjusted to The target wind speed was changed.

The test results are shown in Table 1. The results are shown in Fig. 1θ, in which the dashed-dotted line represents the actual wind speed in the pipe, and -0- represents the indicated wind speed of the fluid pressure sensing device.

Table 11 (27) Examples and performance tests regarding the fluid pressure device of the present invention have been described above. In the examples and those used for testing, the total pressure measuring tube and static pressure measuring tube were cylindrical.
Not limited to this shape, especially for the total pressure measuring tube, it is desirable to have a streamlined shape in consideration of the influence on static pressure measurement. Furthermore, in consideration of the correction coefficient for the actual wind speed, that is, the relative error, the shape is not limited to the above shape, but may be a polygonal shape or any shape that takes into account the ease of connection with the static pressure measuring tube.

However, according to the above test results, it is preferable to install the static pressure measurement hole at the displacement angle θ of the intersection of the measurement curve and the set wind speed because the measured value and the actual wind speed will be equal. However, the actual wind speed can be determined from the relative error even at other displacement angles θ, and this means that the displacement angle θ is 7.
The same applies when the angle is 0° or more.

As described above, the fluid pressure sensing device of the present invention has a pipe having an appropriate number of total pressure measurement holes (28) facing upstream in the flow direction, with the longitudinal direction perpendicular to the flow direction of the fluid in the pipe. A pressure measuring tube, and a static pressure measuring tube having a larger diameter than the above total pressure measuring tube having an appropriate number of static pressure measuring holes at positions at appropriate angles to the flow direction, and the above total pressure. Since the measuring tube and the static pressure measuring tube are integrally joined so that the static pressure measuring tube is located on the downstream side, it is possible to provide a simple structure at a low cost, and the pipe for the fluid in the pipeline can be provided easily. It was also possible to simultaneously measure the pressure at each dividing point for the road cross-sectional area. Moreover, due to the above structure, the pressure loss due to the fluid pressure sensing device of the present invention can be reduced.
Furthermore, there is no fluctuation in accuracy even with changes in wind speed, and effective accuracy can be exhibited, resulting in extremely high practicality.

[Brief explanation of the drawing]

The drawings illustrate a preferred embodiment of the invention, and FIG. 1 is a perspective view of the fluid pressure sensing device of the invention. Figure 2 shows
FIG. 3 is a partially sectional front view, and FIG. 9 is a right side view. Chapter S
The figure is a perspective view showing a preferred embodiment in which the fluid pressure sensing device of the present invention is installed in the middle of an actual pipeline. FIGS. 6 to 10 are diagrams in which measurements of the fluid pressure sensing device of the present invention in various tests were compared with measurements using a pitot tube to examine accuracy. 1...Fluid pressure sensing device 2...Total pressure measurement tube 3...Static pressure measurement tube 4...Total pressure measurement hole 5...Static pressure measurement hole Commissioner of the Japan Patent Office Shima 1
) Haruki Tono 1. Indication of the case: Patent Application No. 81151 of 1981 2, Title of the invention: Fluid pressure sensing device 6, Person making the amendment: Relationship to the case: Patent applicant: 25-18 Shimogo, 4-chome, Shinjuku-ku, Tokyo (Wetsu) Representative of Master Co., Ltd. Person: Yasuo Yamamoto 4, Agent 6, Contents of the amendment (1) In the second line of page 6 of the specification, [N, through “6J” is amended to read “N, through ygJ.”

Claims (1)

[Claims] The direction perpendicular to the direction of fluid flow in the pipe is the longitudinal direction,
A total pressure measuring tube having an appropriate number of total pressure measuring holes facing upstream in the flow direction, and the total pressure measuring tube having an appropriate number of static pressure measuring holes opened at a position at an appropriate angle to the flow direction. A fluid pressure system comprising a static pressure measuring tube with a larger diameter, the total pressure measuring tube and the static pressure measuring tube being integrally joined so that the static pressure measuring tube is located on the downstream side. Sensing device.